This disclosure relates in general to removable disk products and, but not by way of limitation, to persistence device reservation.
There are removable hard drives that can attach to the various connections of a computer (SATA, eSATA, USB, PATA, SCSI, FireWire, etc.). The removable hard drives are attached to the computer and mounted to have a drive letter assigned by the operating system (OS). Certain other media reserve a drive letter waiting for media insertion such as floppy disks and compact discs. Hard drives do not reserve a drive letter until mounted.
Tape cartridges typically require specialized tape drives that spool and play tape media. These tape drives use SCSI commands and SCSI interfaces, and are customized for particular tapes. Larger capacity tapes are developed on occasion, but old tape drives cannot read the new tapes. Users upgrade their drives to use the new tapes, but often the upgraded drives do not read old type formats.
Custom drivers are known to interface with tape or other drivers. Where these drivers are subject to Open Source licensing, they are easy to analyze and possibly thwart security measures. There are good reasons to authenticate and authorize cartridges, but if the security measures are well known, it is likely the security measures will be hacked. Often the price of tape drives are subsidized with the strategy being to recover revenue from the tape cartridges.